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Search: id:A066362
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| A066362 |
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a(n) = least k > n such that EulerPhi(k) < EulerPhi(n), if such a k exists; otherwise a(n) = 0. |
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+0 2
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| 0, 0, 0, 0, 6, 0, 8, 0, 10, 0, 12, 0, 14, 0, 18, 18, 18, 0, 20, 0, 22, 24, 24, 0, 26, 30, 28, 30, 30, 0, 32, 36, 34, 36, 36, 0, 38, 40, 40, 42, 42, 0, 44, 48, 46, 48, 48, 0, 50, 54, 52, 54, 54, 60, 56, 60, 58, 60, 60, 0, 62, 66, 64, 66, 66, 0, 68, 70, 70, 0, 72, 0, 74, 78, 76, 78, 78, 0
(list; graph; listen)
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OFFSET
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1,5
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COMMENT
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If a(n) = 0, then from n onwards, EulerPhi will not go below its value at n.
The first odd term in this sequence is a(314) = 315. - Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Oct 25 2006
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EXAMPLE
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a(2) = 0 since there is no k > 2 for which EulerPhi(k) < 1 = EulerPhi(2). a(5) = 6 since for k = 6, EulerPhi(6) = 2 < 4 = EulerPhi(5).
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CROSSREFS
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Cf. A000010, A036912, A036913.
Sequence in context: A021626 A059956 A011393 this_sequence A083680 A010491 A085609
Adjacent sequences: A066359 A066360 A066361 this_sequence A066363 A066364 A066365
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KEYWORD
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nonn
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AUTHOR
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Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Dec 20 2001
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EXTENSIONS
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More terms from Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Oct 25 2006
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